i have 99 auto- xlt 4x4 3.0 MY gas mileage is terrible!!!!! on highway i barely hit 70 and im at 3100RPM is this normal?!?!? or do i have bad tranyy? alredy did fluid and filter... please help and tell me if your truck does same or where it is,, i have 32`s

 

sounds like its not going into overdrive.

 

it is,,, cuase i hit overdrive button to turn it off and it does up another 300-450 rpm..

 

Lock up torque converter engaging? When you get up to speed the revs should drop a bit suddenly as the lock up engages in the torque converter. Press on the gas, it will disengage and revs will go up BEFORE it downshifts as the torque converter is put back in the drivetrain.

When the lock up converter is engaged, you are basically the same as a manual transmission in whatever gear you're in -- there's no longer the "cushioning" effect of the torque converter which wastes power.

Without the lock up working, you'll have lousy mileage and higher highway RPM's.

 

ok so i need new one??? i tried every pedal trick in book it just dont work i ned to replace somehting... wut u think T-converter?????

 

Either the converter clutch or the control of the clutch. Get thee to someone who can properly diagnose it -- don't throw parts at it, lol.

 

My truck is identical to yours, and mine does the same thing. Mine hits about 2900-3000. Though i dont have 32's

Could it just be the engine?